Thermally insulated container

ABSTRACT

A thermally insulated container is provided which includes a tubular inner container part having a closed bottom and an open top end; a tubular outer container part having a closed bottom and an open top end, for receiving therein the tubular inner container part; and a connection member. With the inner container part received in the outer container part, the connection member is disposed between an upper end portion of the inner container part and an upper end portion of the outer container part to define a sealed space having a predetermined size between the outer peripheral surface of the inner container part and the inner peripheral surface of the outer container part.

TECHNICAL FIELD

The present invention relates to a thermally insulated container havinga multiple wall structure.

BACKGROUND ART

The following thermally insulated containers are being practically used,e.g., as mugs: thermally insulated containers having a multiple wallstructure including inner and outer container parts definingtherebetween a sealed space having a predetermined size so as to keepits contents at an elevated or reduced temperature. A method formanufacturing such a thermally insulated container is disclosed e.g., inthe below-identified Patent Document 1. In this method, while keeping apredetermined gap between an externally mounted molded member(corresponding to the outer container part) and an internally mountedmolded member (corresponding to the inner container part), the diameterof an open end portion of the externally mounted molded member isreduced until the open end portion of the outer molded portion isbrought into close contact (pressure contact) with an open end portionof the internally mounted molded member, thereby forming a joint portionat which the molded members are joined together. Air may be left in thegap between the inner and outer molded members, or this gap may be in avacuum state. (See, e.g., paragraphs 0019 to 0020 and FIG. 3 of PatentDocument 1.)

The inner and outer container parts can be fixedly joined together byclosely pressing them against each other as disclosed in Patent Document1, or can be integrally joined together by metal welding if thecontainer parts are made of metal, or by plastic welding if thecontainer parts are made of resin.

PRIOR ART DOCUMENT(S) Patent Document(s)

Patent document 1: Japanese Unexamined Patent Application PublicationNo. 2008-221317

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In order to fixedly/integrally join the inner and outer container partsby pressing them against each other as disclosed in Patent Document 1,or by metal welding, plastic welding, etc., an elaborate device and/or askilled metal welder is needed, which increases the manufacturing costor makes mass-production difficult. Also, if the inner and outercontainer parts are integrally joined together by metal welding, sincethe same metal is preferably used for the inner and outer containerparts, variations of metals selectable for the inner and outer containerparts are limited.

A thermally insulated container having such a multiple wall structurecan be heated directly if it has a vacuum interior structure, but cannotbe heated directly if air is present in the container, because suchdirect heating will expand the air. However, a user may not be able todetermine whether or not the thermally insulated container has a vacuuminterior structure, and, in this case, the user may have trouble whenheating the container.

It is an object of the present invention to provide a thermallyinsulated container having a multiple wall structure which can beconstructed in a simple manner, and which is capable of keeping itscontents at an elevated or reduced temperature.

Means for Solving the Problems

In order to achieve the above object, the present invention provides athermally insulated container comprising: a tubular inner container parthaving a closed bottom and an open top end; a tubular outer containerpart having a closed bottom and an open top end, wherein the tubularinner container part is received in the tubular outer container part;and a connection member, wherein, with the tubular inner container partreceived in the tubular outer container part, the connection member isdisposed between an upper end portion of the tubular inner containerpart and an upper end portion of the tubular outer container part so asto define a sealed space having a predetermined size between an outerperipheral surface of the tubular inner container part and an innerperipheral surface of the tubular outer container part.

By connecting the inner and outer container parts together through theconnection member, it is possible to omit welding or a similartime-consuming step, and thus to reduce the manufacturing cost of athermally insulated container having a multiple wall structure andcapable of keeping its contents at an elevated or reduced temperature.Also, by removing the inner container part from the outer containerpart, it is possible to conveniently heat only the inner container part.It is also possible to separately use the inner container part and theouter container part as independent containers, instead of using theentire container as a double-walled thermally insulated container. Forexample, two users can separately use the inner container part and theouter container part, or a single user can put a food into the innercontainer part, and a beverage into the outer container part.

In the thermally insulated container, it is preferable that the tubularinner container part has an outer periphery including a tapered surfaceof which an outer diameter decreases toward a bottom end of the tubularinner container part, and that the connection member has an innerperiphery including a tapered surface of which an inner diameterdecreases in an axial direction of the connection member such that thetapered surface of the connection member is disposed along the taperedsurface of the tubular inner container part.

By forming such tapered surfaces on both of the inner container part andthe connection members, when the inner container part is insertedthrough the connection member with the connection member fitted to theupper end portion of the outer container part, the inner container partis smoothly guided by the connection member so as to become coaxial withthe outer container part. As a result, a circumferential gap having auniform size is defined between the inner peripheral surface of theouter container part and the outer peripheral surface of the innercontainer part, thereby providing an improved ability to keep thecontents at an elevated or reduced temperature. Also, when the innercontainer part is inserted, the tapered surfaces of the inner containerpart and the connection member come into surface contact with eachother, thereby preventing the inner container part from being furtherinserted. As a result, a gap having a predetermined size is definedbetween the bottom surfaces of the inner container part and the outercontainer part. Since the bottom surfaces of the inner and outercontainer parts are kept out of contact with each other, the contents ofthe container can be reliably kept at an elevated or reducedtemperature.

In the thermally insulated container having such a tapered surface onits inner container part, the connection member preferably includes: aplurality of radially inwardly rising protrusions on a radially innersurface of an upper end portion of the connection member; and aplurality of radially inwardly rising protrusions on a radially innersurface of a lower end portion of the connection member.

By forming such protrusions, at the initial stage of the insertion ofthe inner container part into the outer container part, it is possibleto reduce the friction between the connection member and the lower endportion (small diameter portion) of the inner container part due totheir contact with each other, and thus to smoothly insert the innercontainer part into the outer container part. Also, upon completion ofthe insertion, the upper end portion (large diameter portion) of theinner container part strongly abuts against the protrusions on the upperend portion of the connection member, so that the inner container partis reliably retained by the connection member (and thus by the outercontainer part). The positions and the number of the protrusions on eachof the upper and lower end portions of the connection member are notparticularly limited, but preferably, such protrusions are disposed atregular intervals in the circumferential direction. For example, suchprotrusions may be composed of three protrusions disposed at 120-degreeintervals, or four protrusions disposed at 90-degree intervals.

In the thermally insulated container, the connection member ispreferably an injection-molded member.

The injection-molded connection member has a predetermined rigidity, andthus is less likely to deform when the inner container part is insertedinto the connection member. This prevents the inner container part frombeing inserted into the outer container part while being tilted relativeto the outer container part, which in turn prevents the gap between theinner and outer container parts from partially becoming narrow, orprevents the inner and outer container parts from partially coming intocontact with each other, thereby maintaining heat-insulating propertiesof the container.

In the thermally insulated container, a material forming the tubularinner container part may be different in kind from a material formingthe tubular outer container part.

In other words, according to the intended use, it is possible to selectan optimal combination of materials for the inner and outer containerparts. For example, the inner container part, for which heat resistanceis required, may be made of stainless steel, whereas the outer containerpart may be made of a resin material, or titanium, aluminum or an alloythereof so as to be light in weight.

In the thermally insulated container, one of a cooling medium and aheating medium may be placed in the sealed space.

By placing a heating or cooling medium in the sealed space, not only isit possible to simply maintain the temperature of the contents of thecontainer such as a beverage, but the contents can also be positivelyheated or cooled. For example, it is possible to make ice cream, or cookfood, in the inner container part. The hearing or cooling medium may be,e.g., refrigerant, ice water or hot water.

Effects of the Invention

Since the multiple wall structure of the thermally insulated containeraccording to the present invention is constructed by the inner containerpart, the outer container part, and the connection member disposedbetween the inner and outer container parts, this thermally insulatedcontainer can be manufactured at a low cost, and still shows sufficientability to keep its contents at an elevated or reduced temperature,compared to a thermally insulated container of which the inner and outercontainer parts are integrally joined together by e.g., welding.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of a thermally insulated container (mug)according to a first embodiment of the present invention.

FIG. 1B is a side view of the thermally insulated container (mug)according to the first embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG. 1B.

FIG. 3 is an enlarged sectional view of a portion of FIG. 2.

FIG. 4 is a perspective view of the thermally insulated container ofFIGS. 1A and 1B.

FIG. 5 is an exploded side view of the thermally insulated container ofFIGS. 1A and 1B.

FIG. 6 is a perspective view of the thermally insulated container ofFIGS. 1A and 1B.

FIG. 7 is a sectional view of a thermally insulated container accordingto a second embodiment of the present invention.

FIG. 8 is a sectional view of a thermally insulated container accordingto a third embodiment of the present invention.

FIG. 9 is a sectional view of a thermally insulated container accordingto a fourth embodiment of the present invention.

FIG. 10 is a sectional view of a thermally insulated container accordingto a fifth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIGS. 1A to 6 illustrate a thermally insulated container 10 according tothe first embodiment of the present invention. The thermally insulatedcontainer 10 is a mug (the mug is also hereinafter denoted by numeral“10”) having a double wall structure, and mainly used outdoors or athome. The mug 10 includes, as its main elements, an inner container part11, an outer container part 12, and a connection member 13.

The inner container part 11 is a tubular member having a closed bottomand an open top end, for holding beverages and other items. The innercontainer part 11 has an outer periphery including, at its portion closeto the top end, a tapered surface 14 of which the outer diameterdecreases toward the bottom end of the inner container part 11. In theembodiment, the inner container part 11 is made of stainless steel, butit may be made of a resin material if high strength or heat resistanceis not required.

The mug 10 may include a lid 15 disposed at the top end opening of theinner container part 11. The lid 15 is formed with a drinking opening 16and an air hole 17 so that, when a beverage flows out of the innercontainer part 11 through the drinking opening 16, air simultaneouslyflows into the inner container part 11 through the air hole 17, therebyenabling the beverage to flow out smoothly. A seal member 18 is disposedat the outer peripheral edge of the lid 15 so as to reliably keep thelid 15 fitted in the inner container part 11.

The thermally insulated container 10 of the embodiment is exemplified asa mug 10 of which the lid 15 has a drinking opening 16 and an air hole17 so that a user can drink the beverage in the inner container part 11with the lid 15 attached. However, the drinking opening 16 and the airhole 17 may be omitted to provide heat insulating and sealing propertiesto the lid 15. The thermally insulated container 10 including such a lid15 can be used not only as a mug 10, but as e.g., a pot or a jar.

The outer container part 12 is a tubular member having a closed bottomand an open top end, in which the inner container part 11 is received.The outer container part 12 has a uniform outer diameter from its topend to its bottom end. In the embodiment, the outer container part 12 ismade of the same material as the inner container part 11, i.e.,stainless steel, but it may be made of a resin material so that heat isnot transferred from the mug 10 to a user's hand gripping the mug 10.Also, if lightness in weight is important, the outer container part 12may be made of titanium, aluminum, or an alloy thereof.

The inner diameter of the outer container part 12 at its open end isequal to the inner diameter of the inner container part 11 at its openend (see FIG. 3). Therefore, instead of putting the lid 15 on the innercontainer part 11, the lid 15 can be put on the top end opening of theouter container part 12, too.

With the inner container part 11 received in the outer container part12, the connection member 13 defines a sealed space having apredetermined size between the outer peripheral surface of the innercontainer part 11 and the inner peripheral surface of the outercontainer part 12. For this purpose, the connection member 13 isdisposed between the upper end portions of the inner and outer containerparts 11 and 12. The connection member 13 has, on its inner periphery, atapered surface 19 of which the inner diameter decreases axiallydownwardly of the connection member 13. The tapered surface 19 isdisposed along the tapered surface 14 of the inner container part 11.The lower end portion of the connection member 13 that is located belowthe tapered surface 19 has a smaller diameter than the upper end portionof the connection member 13 that is located above the tapered surface19. The connection member 13 is formed by injection molding of a resinmaterial, and is rigid enough not to be deformed to a large degree whenthe inner container part 11 is inserted into the outer container part12.

The connection member 13 includes a plurality of radially inwardlyrising protrusions 20 on the radially inner surface of its upper endportion; and a plurality of radially inwardly rising protrusions 21 onthe radially inner surface of its lower end portion (see FIG. 6). Theprotrusions 20 and 21 are ribs extending in the axial direction of theconnection member 13. In the embodiment, the protrusions 20, 21 on eachof the upper and lower end portions of the connection members 13 areexemplified as three protrusions circumferentially disposed at intervalsof 120 degrees, but the positions and the number of the protrusions 20,21 are not particularly limited, and may be altered as necessary.

A seal member 22 is disposed at the radially outer surface of the lowerend portion of the connection member 13. The seal member 22 is made ofsilicon resin, and reliably keeps the connection member 13 fitted in theouter container part 12 even if the connection member 13 is a rigidinjection-molded member. While, in the embodiment, the connection member13 and the seal member 22 are separate members, they may be formedintegrally with each other using a relatively soft material such assilicon resin.

The connection member 13 partially covers the upper end portion of theinner container part 11 (see FIG. 2), thus reducing the contact area ofa user's lips with the upper end portion of the inner container part 11.This minimizes the sensation of heat felt when the user's lips touch theinner container part 11 with a high-temperature beverage in the mug 10(i.e., in the inner container part 11.

It is now described how the mug 10 is assembled. First, as illustratedin FIG. 6, the connection member 13 is fitted into the top end openingof the outer container part 12. Then, the inner container part 11 isinserted through the connection member 13 and into the outer containerpart 12 so as to be arranged coaxially with the outer container part 12.At the initial stage of the insertion, the protrusions 21 of theconnection member 13 on the radially inner surface of its lower endportion come into contact with the lower end portion (small diameterportion) of the inner container part 11. Since the protrusions 21 comeinto substantially line contact with the lower end portion of the innercontainer part 11, and are shaped so as to guide the insertion of thelower end portion of the inner container part 11, it is possible tominimize the friction between the inner container part 11 and theconnection member 13, and thus to smoothly insert the inner containerpart 11.

Also, even if the inner container part 11 and the outer container part12 are not coaxial with each other at the initial stage of theinsertion, the inner container part 11 eventually becomes coaxial withthe outer container part 12 due to the tapered surface 14 of the innercontainer part 11 coming into surface contact with the tapered surface19 of the connection member 13.

Also, upon completion of the insertion, the protrusions 20 of theconnection member 13 on the radially inner surface of its upper endportion strongly abut against the upper end portion (large diameterportion) of the inner container part 11, so that the inner containerpart 11 is reliably retained by the connection member 13 (and thus bythe outer container part 12). This reliably prevents the separation ofthe inner container part 11 when the mug 10 is tilted.

As necessary, a heating or cooling medium such as refrigerant, ice wateror hot water may be placed in the sealed space between the innercontainer part 11 and the outer container part 12 so that the contentsof the mug 10 can be not only simply kept at an elevated or reducedtemperature, but also positively heated or cooled.

FIG. 7 illustrates a mug 10 according to the second embodiment of thepresent invention. The mug 10 of the second embodiment is identical inbasic structure to the mug 10 of the first embodiment, but the shapes ofthe inner container part 11, outer container part 12 and connectionmember 13 are different.

Specifically, the mug 10 of the second embodiment has, besides thetapered surface on the inner container part 11, an additional taperedsurface on the outer container part 12, and thus the outer shape of themug 10 is such that its lower end portion is slimmer than its upper endportion. Also, two seal members 22 are disposed on the outer peripheryof the connection member 13 so as to be vertically spaced apart fromeach other, thereby ensuring airtightness between the outer containerpart 12 and the connection member 13. An externally mounted member 23 isdisposed on the outer peripheral surface of an upper end portion of theouter container part 12. The externally mounted member 23 is provided toenable a user to grip the mug 10 more reliably (easily).

FIG. 8 illustrates a mug 10 according to the third embodiment of thepresent invention. The mug 10 of the third embodiment is identical inbasic structure to the mug 10 of the first embodiment, but the shape ofthe connection member 13 is different.

Specifically, the connection member 13 of the mug 10 according to thethird embodiment has no seal member 22, and is wedged between the innerand outer container parts 11 and 12 by the force with which the innercontainer part 11 is fitted into the outer container part 12. In thisarrangement, since the shape of the connection member 13 can besimplified, it may be possible to reduce the manufacturing cost. Theconnection member 13 of this embodiment is preferably made of siliconresin, a material having flexibility. An externally mounted member 23 isdisposed on the outer peripheral surface of the upper end portion of theouter container part 12. The externally mounted member enables a user togrip the mug 10 more reliably (easily).

FIG. 9 illustrates a mug 10 according to the fourth embodiment of thepresent invention. The mug 10 of the fourth embodiment is identical inbasic structure to the mug 10 of the first embodiment, but the shapes ofthe inner container part 11, outer container part 12 and connectionmember 13 are different.

Specifically, the inner container part 11 of the mug 10 according to thefourth embodiment has a tapered surface 14 near its top end, and has anouter diameter that gradually decreases from the tapered surface 14 tothe bottom end of the inner container part 11. The outer container part12 has an outer diameter that gradually decreases from a portion of theouter container part 12 close to its top end to its bottom end.Therefore, the outer shape of the mug 10 is such that its lower endportion is slimmer than its upper end portion. The connection member 13has no seal member 22, and is wedged between the inner and outercontainer parts 11 and 12 by the force with which the inner containerpart 11 is fitted into the outer container part 12. In this arrangement,since the shape of the connection member 13 can be simplified, it may bepossible to reduce the manufacturing cost, as in the third embodiment.

FIG. 10 illustrates a mug 10 according to the fifth embodiment of thepresent invention. The mug 10 of the fifth embodiment is identical inbasic structure to the mug 10 of the first embodiment, but the shapes ofthe inner container part 11, outer container part 12 and connectionmember 13 are different.

Specifically, the inner and outer container parts 11 and 12 of the mug10 according to the fifth embodiment are identical in shape to eachother, and each has an outer diameter that gradually decreases from aportion of the container part close to its top end to its bottom end.The connection member 13 has no seal member 22, and is wedged betweenthe inner and outer container parts 11 and 12 by the force with whichthe inner container part 11 is fitted into the outer container part 12.In this arrangement, since the inner and outer container parts 11 and 12can be formed with the same mold, and the shape of the connection member13 can be simplified, it may be possible to reduce the manufacturingcost.

The above embodiments are mere examples in every respect. For example,the shapes of the elements of the mug 10, such as the inner containerpart 11, the outer container part 12 and the connection member 13, maybe altered as necessary, provided that the object of the presentinvention, i.e., to provide a thermally insulated container having amultiple wall structure which can be constructed in an simple manner,and which is capable of keeping its contents at an elevated or reducedtemperature, can be achieved.

For example, while the mug 10 is exemplified as having a double wallstructure in each of the above embodiments, the mug 10 may have a tripleor more wall structure. Such a mug 10 may show an improved ability tokeep its contents at an elevated or reduced temperature.

While the mug 10 having a double wall structure described in each of theabove embodiments is capable of keeping its contents at an elevated orreduced temperature, a portion of the outer container part 12 or theconnection member 13 of the mug 10 may have the function of a simplifiedvalve element or air pump capable of discharging air in the spacebetween the two walls of the mug (thereby creating a vacuum or adecompressed state in this space). This further improves the ability ofthe mug 10 to keep its contents at an elevated or reduced temperature,compared to when there is an air layer at atmospheric pressure in thespace between the two walls of the mug 10.

DESCRIPTION OF REFERENCE NUMERALS

10: thermally insulated container (mug)

11: inner container part

12: outer container part

13: connection member

14: tapered surface (of the inner container part)

15: lid

16: drinking opening

17: air hole

18: seal member (for the lid)

19: tapered surface (of the connection member)

20: protrusion (on the upper end portion of the connection member)

21: protrusion (on the lower end portion of the connection member)

22: seal member (for the connection member)

23: externally mounted member

1. A thermally insulated container comprising: a tubular inner containerpart having a closed bottom and an open top end; a tubular outercontainer part having a closed bottom and an open top end, wherein thetubular inner container part is received in the tubular outer containerpart; and a connection member, wherein, with the tubular inner containerpart received in the tubular outer container part, the connection memberis disposed between an upper end portion of the tubular inner containerpart and an upper end portion of the tubular outer container part so asto define a sealed space having a predetermined size between an outerperipheral surface of the tubular inner container part and an innerperipheral surface of the tubular outer container part.
 2. The thermallyinsulated container according to claim 1, wherein the tubular innercontainer part has an outer periphery including a tapered surface ofwhich an outer diameter decreases toward a bottom end of the tubularinner container part, and wherein the connection member has an innerperiphery including a tapered surface of which an inner diameterdecreases in an axial direction of the connection member such that thetapered surface of the connection member is disposed along the taperedsurface of the tubular inner container part.
 3. The thermally insulatedcontainer according to claim 2, wherein the connection member includes:a plurality of radially inwardly rising protrusions on a radially innersurface of an upper end portion of the connection member; and aplurality of radially inwardly rising protrusions on a radially innersurface of a lower end portion of the connection member.
 4. Thethermally insulated container according to claim 1, wherein theconnection member is an injection-molded member.
 5. The thermallyinsulated container according to claim 1, wherein a material forming thetubular inner container part is different in kind from a materialforming the tubular outer container part.
 6. The thermally insulatedcontainer according to claim 1, wherein one of a cooling medium and aheating medium can be placed in the sealed space.
 7. The thermallyinsulated container according to claim 2, wherein the connection memberis an injection-molded member.
 8. The thermally insulated containeraccording to claim 3, wherein the connection member is aninjection-molded member.
 9. The thermally insulated container accordingto claim 2, wherein a material forming the tubular inner container partis different in kind from a material forming the tubular outer containerpart.
 10. The thermally insulated container according to claim 3,wherein a material forming the tubular inner container part is differentin kind from a material forming the tubular outer container part. 11.The thermally insulated container according to claim 4, wherein amaterial forming the tubular inner container part is different in kindfrom a material forming the tubular outer container part.
 12. Thethermally insulated container according to claim 7, wherein a materialforming the tubular inner container part is different in kind from amaterial forming the tubular outer container part.
 13. The thermallyinsulated container according to claim 8, wherein a material forming thetubular inner container part is different in kind from a materialforming the tubular outer container part.
 14. The thermally insulatedcontainer according to claim 2, wherein one of a cooling medium and aheating medium can be placed in the sealed space.
 15. The thermallyinsulated container according to claim 3, wherein one of a coolingmedium and a heating medium can be placed in the sealed space.
 16. Thethermally insulated container according to claim 4, wherein one of acooling medium and a heating medium can be placed in the sealed space.17. The thermally insulated container according to claim 5, wherein oneof a cooling medium and a heating medium can be placed in the sealedspace.
 18. The thermally insulated container according to claim 7,wherein one of a cooling medium and a heating medium can be placed inthe sealed space.
 19. The thermally insulated container according toclaim 8, wherein one of a cooling medium and a heating medium can beplaced in the sealed space.
 20. The thermally insulated containeraccording to claim 9, wherein one of a cooling medium and a heatingmedium can be placed in the sealed space.